
function f1() {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      console.log('1秒');
      resolve()
    }, 1000)
  })
}

function f2() {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      console.log('300豪秒');
      resolve()
    }, 300)
  })
}

function f3() {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      console.log('500豪秒');
      resolve()
    }, 500)
  })
}
async function get1() {
  await f1().then(() => { f3().then(() => { f2() }) })
}
get1()